Description

Summary

To compare the efficacy of MEDI-551 versus placebo in reducing the risk of an NMO/NMOSD attack in subjects with NMO/NMOSD.

Official Title

A Double-masked, Placebo-controlled Study With Open-label Period to Evaluate the Efficacy and Safety of MEDI-551 in Adult Subjects With Neuromyelitis Optica and Neuromyelitis Optica Spectrum Disorders

Details

MEDI-551 is a genetically engineered humanized monoclonal antibody that binds to the B cell specific surface antigen CD19 resulting in the depletion of B cells. CD19 positive (CD19+) B-lineage plasmablasts are responsible for the production of autoantibodies against the AQP4 channel protein.

The main objective of this study is to determine whether MEDI-551 compare to placebo decreases the risk of an attack in subjects with NMO/NMOSD.

This is a multicenter, multinational, randomized, double-masked, placebo controlled study with an open-label extension period to evaluate the efficacy and safety of intravenous (IV) MEDI-551 in adult subjects with NMO/NMOSD.

After a screening period, eligible subjects will enter a randomized-controlled period (RCP) of maximum 197 days where they will be randomized in a 3:1 ratio to receive either IV MEDI-551 or placebo. NMO/NMOSD attacks will be evaluated by the investigator and confirmed against the attack criteria by an independent Adjudication Committee (AC). Subjects for whom the attack was confirmed by the AC will be given the option to enroll into an open label period (OLP) with MEDI-551 treatment. Subjects who complete the RCP without experiencing an attack will be given the option to enroll into an OLP with MEDI-551 treatment. The OLP will continue for a minimum of 1 year and a maximum of 3 years after the last subject enter the OLP.

All subjects who discontinue from the RCP or the OLP will continue in a Safety Follow-up for a total of 12 months from last dose to evaluate the long-term safety of the investigational product.